Does Dairy Cause Acne?

Acne is the most common persistent inflammatory skin condition worldwide, but it is more than just a physical concern. Its impact stretches beyond the surface, significantly influencing one’s self-esteem and confidence during adolescence and beyond. The psychological effects of acne have been compared with those of chronic diseases such as asthma, arthritis, and diabetes.

Acne is most common in adolescents aged 15 to 17 years. However, data shows that around 50% of adults aged 25 or older in Western countries also suffer from acne¹, with more women being affected than men.

Causes of acne

Acne is a complex condition with hormone disorders and genetic predispositions contributing to its development, alongside lifestyle behaviours such as smoking, the use of cosmetic products, stress, exposure to pollution, and other lifestyle behaviours, including diet. It mainly occurs due to the blockage of hair follicles by oil and dead skin cells, with potential aggravation from Propionibacterium acnes bacteria, leading to inflammation and pimple formation.

The condition primarily affects areas with a high number of oil glands, such as the face, neck, chest, shoulders, and back.

Types of Acne

• White and Blackheads (comedones): non-inflammatory acne characterised by closed (whiteheads) or open (blackheads) plugged pores.
• Papules and Pustules: inflammatory acne involving red, tender bumps (papules) or pus-filled lesions (pustules).
• Nodules and Cysts: more severe forms of acne involving deep, painful lumps (nodules) or large, pus-filled lesions (cysts) that can cause scarring.

Connection Between Foods and Acne Flare-ups

The relationship between diet and acne has been a subject of interest. While individual responses vary, certain foods have been associated with exacerbated acne. Some examples are high glycaemic index (GI) foods, which are foods that cause blood sugar to rise fast, promoting inflammation in the cells, fast or junk foods and dairy products. For example, a study that looked at dietary patterns of almost 25000 French adults found that a diet high in fat, sugar, milk and sugary drinks was directly associated with acne occurrence². Another robust review of 14 studies found that dairy, including cheese, milk and yoghurt, were associated with the occurrence of acne in children and adults (aged 7 to 30 years)³.

Understanding Dairy Production

Up to 90% of milk and other dairy products come from pregnant cows. To help you understand the possible ways dairy can cause acne, let’s take a closer look at how dairy is produced.

A female cow doesn’t produce milk until after she has her first baby calf. She then feeds her calf for about a month, after which she starts getting milked regularly for dairy production. The cow is made pregnant again about six weeks after giving birth, and she keeps getting milked throughout the next ten-month pregnancy. She stops giving milk for a few weeks just before she has another calf. This process, which leads to the cow producing fresh milk after giving birth, repeats several times.

How Dairy may Cause Acne

1. Hormones in Dairy: because dairy cows are often pregnant, their milk contains hormones, including androgens and growth hormone, which can influence oil production in human skin and result in acne.
2. Insulin-Like Growth Factor 1 (IGF-1): milk contains IGF-1, which is a hormone that promotes growth. After all, milk is produced to grow a baby calf into a cow. This hormone is similar to insulin, thus raising blood sugar. Spikes in blood sugar can increase the production of oil and promote inflammation, potentially causing acne.
3. Dairy Impact on Insulin Levels: dairy products, especially those low in fat, can raise insulin levels. This is in part because fat is often replaced by sugar in low-fat products. Elevated insulin can boost oil production and the proliferation of skin cells, potentially clogging pores and leading to acne.
4. Inflammatory Factors: Some individuals may have an inflammatory response to the proteins found in dairy, such as whey and casein, and inflammation exacerbates acne.

Practical advice

For those struggling with acne, it may be worth experimenting with reducing dairy intake to see if it makes a difference. However, it’s crucial to ensure you’re still receiving adequate nutrition and substituting dairy with the right nutrients and because nutritional needs are extremely individualised, it is always recommended to seek advice from a qualified health professional before making drastic changes to your diet.

References:

1. Semedo, D., et al. (2016). Adult Acne: Prevalence and Portrayal in Primary Healthcare Patients, in the Greater Porto Area, Portugal.Acta medica portuguesa, 29 (9), 507–513. https://doi.org/10.20344/amp.6626
2. Penso, L. et al. (2020) Association Between Adult Acne and Dietary Behaviors: Findings From the NutriNet-Santé Prospective Cohort Study. JAMA dermatology (Chicago, Ill.). [Online] 156 (8), 854–862.
3.  Juhl, C. R. et al. (2018) Dairy intake and acne vulgaris: A systematic review and meta-analysis of 78,529 children, adolescents, and young adults. Nutrients. [Online] 10 (8), 1049.